


But You Do Something I've Never Known

by liminal_mess



Category: Shadowhunters (TV)
Genre: Alec Lightwood Birthday Surprise, Alec in lingerie, Anal Fingering, Anal Sex, Blow Jobs, Bottom Alec Lightwood, Discord: Malec Server, Dom/sub Undertones, Explicit Sexual Content, Kissing, M/M, Plot What Plot/Porn Without Plot, Praise Kink, Top Magnus Bane, specifically a corset and panties
Language: English
Status: Completed
Published: 2020-09-19
Updated: 2020-09-19
Packaged: 2021-03-07 21:54:24
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,805
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26544796
Author URL: https://archiveofourown.org/users/liminal_mess/pseuds/liminal_mess
Summary: After Alec's birthday party, Magnus has a couple more surprise gifts for him that make the rest of their night very interesting.
Relationships: Magnus Bane/Alec Lightwood
Comments: 9
Kudos: 105





	But You Do Something I've Never Known

**Author's Note:**

> This was written as a companion fic to the beautiful art created by [AceOnIce](https://archiveofourown.org/users/AceOnIce/pseuds/AceOnIce), [Here's the link to the art on tumblr.](https://aceon-ice.tumblr.com/post/629256453807538176/enjoy-some-boys-in-corsets-my-contribution-for) It's also embedded below! Thanks so much Amelia for beta'ing this too. 💕  
> This is also for the Alec Lightwood Birthday Surprise event in the [Malec Discord Server](https://discord.gg/5nBgEp8). Come join us! Oh and, the title of this fic is from the song Be the One by Sinead Harnett.

The last of their guests, Izzy, finally says goodbye with a warm hug for both of them. “I should be heading out, work tomorrow. But seriously, Magnus, best party ever, you’ve really outdone yourself.” Izzy says, her voice slurring slightly from the alcohol.

“What can I say, your brother provides endless inspiration,” Magnus says, beaming at her, before winking in Alec’s direction. 

Alec actually _giggles_ , because he’s also still a little buzzed, and then immediately claps a hand over his mouth, embarrassed at the sound that escaped his lips. 

Izzy shakes her head as Magnus laughs. She’s still amazed at how much happier Alec has been since he met Magnus. And based on all the attention Magnus had put into the birthday party tonight to make it perfect for him, it’s even more clear as to why that is. 

Magnus closes the door behind her as she walks out with a wave and he turns around, leaning back against the wood. “Hey you,” he says softly, happy that they’re finally alone. He takes a moment to really look at Alec. 

His husband looks more breathtaking than usual, with flushed cheeks and messy hair, probably from his siblings messing it up to annoy him. The outfit he chose for tonight features a green dress shirt, something he wouldn’t usually wear. The shirt makes his eyes pop and it looks even hotter on him with the sleeves rolled up. 

Magnus’ thoughts must be written all over his face because when he looks into Alec’s eyes, the returned gaze is hot and wanting. Alec closes the short distance between them and kisses him urgently. Magnus’ hands come up around Alec’s waist as he deepens the kiss, teasing Alec’s mouth open with his tongue. 

Alec must feel how Magnus is growing hard against him because he rolls his hips, causing sparks of pleasure to shoot through Magnus’ body. He gasps against Alec’s mouth, hands already moving to tug his shirt out of his pants, when he suddenly remembers that he has one more present for Alec that he saved for when they’re alone.

“Wait,” Mangus says, pulling back and causing Alec to groan at the loss, “I have another gift for you that I think will make this night more interesting. Bedroom.” 

Alec looks at him curiously, but Magnus doesn’t say anything more, just leads him along by the hand towards their bedroom. As Alec sits down on the bed, Magnus retrieves a wrapped box from the closet that he then hands over to Alec with a mischievous twinkle in his eyes. 

The box is wrapped in shiny blue paper with a bow on top, which makes Alec smile. He opens the box and just stares for a moment, flushing slightly. He darts his eyes up at Magnus and the other man can see how his pupils have dilated wider with want.

“Fuck, Magnus. You got me one? Do you… should I put it on now?” 

“Yes, but look under it first, there’s something else in there I think you’ll like.”

When Alec pushes the red corset aside, he finds lacy black panties underneath. They’re delicate and beautiful. His breath hitches as another burst of desire blooms low in his gut. 

“You’re going to kill me on my birthday,” he says with a shaky chuckle.

Magnus leans in for a quick kiss, and then draws back, hands coming up to cradle Alec’s face.

”I haven’t even started yet, darling,” he murmurs, swiping a thumb across Alec’s cheekbone. Alec shivers slightly in anticipation at all the promise those words hold.

“Do you wanna wait in the living room? So you can see it all together?” Alec asks, turning to kiss the other man’s palm gently. 

Magnus does like the thought of walking into the room to that sight so he moves to leave before deciding to press one more kiss to Alec’s mouth that was meant to be a quick peck. Except Alec decides to nip at his bottom lip, which makes Magnus deepen the kiss in response. Alec pushes him away gently after a few moments, chuckling breathlessly. 

“You’re a menace, you know that?” Magnus sighs and gets up to actually leave this time, leaving behind a grinning Alec. As he waits outside the door, he feels the excitement for the rest of the night fluttering in his chest. 

Alec is always hesitant in asking for what he wants sexually, but when he had first seen the corset vest that Magnus is now wearing in his closet, he had asked about it with sudden desire in his expression. The next time Magnus wore it, Alec had all but jumped him in his eagerness to get his hands on Magnus. So, although Alec never said it out loud, Magnus had put two and two together and bought one for him that was more for the bedroom. And, well, the site had some really pretty men’s panties that he knew would look amazing on Alec, so decided to get that too.

“Magnus?” He hears Alec say from the room, “You can come back in.” 

When he enters the room, Alec is turned around, so he gets a full view of how perfect his ass looks in the lacy panties. They accentuate his curves in a way that makes Magnus want to touch them urgently. “Can you tighten this?” Alec asks, turning to look at him shyly. 

Magnus just nods, words escaping him as he’s too busy figuring out where to look first _._ The red corset stands out against Alec’s pale skin and highlights the black of runes on his neck and back beautifully. Magnus can’t help but run his palm along Alec’s ass, squeezing and feeling the delicate cloth of the lace. 

“Fuck, Alexander, you look so good in these.” Magnus presses a kiss to the rune on his upper back, making Alec shiver both at the kiss and the compliment, goosebumps appearing on his arm. 

“How tight do you want it, darling?” Magnus murmurs against Alec’s skin as he takes hold of the ties that will allow him to tighten the corset.

“Mm, make it as tight as you want it, I trust you,” he says, and god, it drives Magnus wild when Alec wants him to take control like this, and Alec knows it. He practically growls as he pulls even tighter, causing Alec’s breath to hitch in response. He knots the strings together and lets go, nipping and sucking at Alec’s ear and whispering, “tell me if it’s too much, okay?” 

Alec gasps and jerks out a quick nod. Magnus turns Alec around in a smooth movement, because he can’t stand it anymore, needs that mouth on his _right now._

He licks into Alec’s mouth, moving his tongue against Alec’s as they kiss open-mouthed and sloppy. He reaches down to run his hand along Alec’s cock, where it’s straining against the panties, circling the head with his thumb. Alec moans against Magnus’ mouth, his hips stuttering up into Magnus’ hand. 

Magnus pulls away slightly, panting as he speaks. “What do you want, Alec?” 

“Fuck, I- I want to taste you, Magnus... please.” He looks completed fucked out already, face flushed, his plump lips bitten red and his hazel eyes almost black with want. 

“Get on your knees.” Magnus says, making it sound like an order, the way he knows Alec loves. 

He obeys immediately, and Magnus takes a second to magic his own clothes away, which he had forgotten to do, since he was focusing on Alec and how incredible he looked in his gifts. He somehow looks even better on his knees as he looks up at Magnus through his long, delicate eyelashes. Magnus can see how the movement of his chest is restricted slightly because of the corset and that, the fact that Alec trusts him to be this vulnerable, turns him on even more. 

Alec licks a strip up his cock, causing Magnus to gasp and snapping his attention back to the moment. Alec pauses to licks the head, staring up at Magnus teasingly before taking more of it into his mouth.

“God, Alexander, you look so perfect like this, on your knees just for me.” Magnus buries his hands in Alec’s hair, pulling slightly. Alec’s eyes flutter closed at the compliment, moaning around the cock as he bobs his head up and down. 

Magnus throws his head back, lost in the warmth of Alec’s mouth as he takes him in deeper with each movement. He can’t help but thrust up, hitting the back of Alec’s throat and gripping his hair tight. Alec gags but doesn’t try to pull off and instead lets Magnus pull back, gasping when he can. He makes a strangled noise at the back of his throat, but he doesn’t move, just looks up at Magnus with his mouth open in an invitation for him to continue fucking his mouth. So Magnus does, snapping his hips in and out as Alec closes his eyes and takes it. He licks up the underside of Magnus’ cock every time he thrusts in, causing Magnus to see stars. 

“Alec, fuck, ah,” Magnus stutters out, hands trembling where they rest in Alec’s hair and already feeling too damn close because of how eager Alec is. He taps Alec’s shoulder lightly for him to stop, because Magnus is going to come if he keeps going like this. Alec rests his head on Magnus’ thigh and sucks deep breaths in, as the other man pulls back. 

Magnus lets him catch his breath and then pulls him up gently, peppering kisses on his neck, along his jaw and his face once he’s standing. “You were so good for me, angel,” he murmurs, smoothing his hands along Alec’s sides. 

He loves to take every opportunity he can to praise Alec in the bedroom, because it’s the only place he’ll accept his praises without question, without trying to deflect or give some of the credit away to someone else. He does still blush a pretty pink though, like he is right now as he uses the chance to suck a bruise onto Magnus’ neck to hide his face too. 

Magnus starts gently pushing Alec back towards their bed, taking his turn to nip and suck at the deflect rune in his husband’s neck, causing him to arch up to give Magnus more room. The back Alec’s knees hit the edge of the bed and he puts one hand back to catch himself as he falls onto the mattress. Magnus goes down with him, continuing to kiss Alec’s neck once he’s on top. The position causes their cocks to rub together, which feels _incredible_ so Magnus pushes up harder, the resulting friction making his knees feel weak. 

“Magnus,” Alec gasps out at the contact, “ _fuck, Magnus,”_ he adds, pushing his hips up to get closer, more.

“Ah, darling, you have to tell me what you want,” he replies, chuckling breathlessly against Alec’s neck. 

“Want you to, ah- want you to fuck me,” Alec pleads, surging up to kiss Magnus and to move his panties aside so he can stroke both their cocks together through the slick of his spit and both of their precome. 

Magnus closes his eyes and moans, riding out the overwhelming sensation of their cocks moving together in Alec’s rough hand. He breaks the kiss to growl out another order, “let me get you ready.” Alec is again, happy to comply, twisting slightly and using his arms to push himself to the head of their bed in one fluid motion. Magnus climbs onto the bed after Alec, pushing his legs up and apart when he gets to him. 

“Do you want me to-“ Alec begins, licking his lips and looking down, before flicking his eyes back up at Magnus’ face. 

“Keep them on,” Magnus says, referring to the panties that are pushed aside already to accommodate Alec’s cock. He pushes them aside further, and snaps his fingers, using magic to slick his fingers up with lube. Alec draws his legs up further, hissing slightly when Magnus teases at his rim. He pushes in one finger and then another, pumping them in and out. Alec is already letting out a whining noise and pushing down onto his fingers to get them in deeper. 

“You look so fucking hot, dressed up in your corset and panties for me and opening up so easy, Alexander,” Magnus murmurs, sliding another finger in and making Alec moan at the pleasurable stretch. 

“Oh, ah, _Magnus_ , god, please please, I want you,” Alec sobs out, pushing down harder at the fingers moving in and out of his hole. 

“Shh, I know, I know, hold on,” Magnus soothes, making quick work of lining up his cock, which he also lubes up with a wave, against Alec’s hole. He pushes in slowly, giving Alec time to adjust, and gasping at the feeling of warmth and tightness that envelops his cock. 

Magnus pushes to the hilt inside of him and takes a second to breathe, checking with a questioning gaze to make sure Alec is ready. He moves back, before snapping his hips forward again, burying himself almost all the way in. Alec moans loudly at the movements, a litany of swears escaping his lips as his hand scrabbles for something to hold on to and slip on the silk sheets. Magnus moves to hold his arms down against the bed as he continues fucking Alec, keeping up the punishing rhythm.

“Hnng, Magnus, _Magnus_ , fuck, god please, harder,” Alec yells out, his head thrown back and his face contorted in pleasure. 

Magnus pushes Alec’s legs up higher, changing the angle in a way that he knows will hit right at Alec’s prostate, and he can tell he does because Alec practically _keens,_ pushing up to meet Magnus’s hips, face slack, his mouth open. He makes the same movement a couple more times and Alec is a withering mess underneath him, his breath hitching as he gets completely lost in the pleasure. “Yes, yes ah, Magnus, yes, like that.”

Magnus knows he’s not going to last much longer with Alex saying his name like that and moaning so sinfully, so he reaches down to Alec’s cock, which is leaking precome steadingly onto the corset. He wants them to reach their crest together because it’s so much better when he can feel Alec coming undone underneath him as he does too. 

“Alec, ah, come for me, I- I’m so close,” he stuttures out, fucking him even harder, the headboard banging against the wall with the effort. And then, with a couple more thrusts, he sees stars, intense pleasure shooting its way through his body. He can feel Alec twitching in his hand and hears him cry out. Magnus opens his eyes with effort, knowing Alec loves to watch his eyes flame gold as he loses control, how it makes his pleasure crest even higher. Alec stares back, gaze scorching with intensity as he comes. 

Magnus keeps fucking into Alec, cock twitching with the last of his orgasm, and then, finally heaves himself off to collapse next to him, panting heavily, sweat pouring down his body. Alec is breathing heavy next to him, eyes closed, just as sweaty, as they both take a moment to recover. Magnus waves his arm tiredly to clean them up and to magic away Alec’s lingerie, knowing the corset must be uncomfortable by now, when he’s not in the heat of the moment. 

“Happy birthday,” he says, turning to face Alec and chuckling, still a little breathless.

Alec laughs and turns towards him too, face flushed, his expression tired but happy. “It’s been a _very_ happy birthday, all thanks to you.” 

“Mm, of course. You deserve everything and more.” Magnus replies softly, cupping Alec’s face and beaming at him. Now that he’s looking at Alec more carefully, he notices that the corset had left red marks where it was pressed against his skin too hard. He traces the line that goes across the top of his chest with gentle, soothing fingers. “Does this hurt? Do you want me to use my magic?”

Alec nods, his eyes fluttering closed as the exhaustion hits him. “Mm, leave them, it’s the good kind of hurt,” he replies, burrowing closer to put his chest on Magnus’ chest. 

Magnus shifts to his back and brings his arms to encircle Alec’s body, moving even closer to tangle their legs together. Another wave of his hand brings a blanket to cover them both, which elicits a soft sigh of satisfaction from Alec. 

“I love you, my Alexander,” he murmurs, turning his head to press a quick kiss against the other man’s forehead.

“Love you too,” Alec mumbles, already half asleep as he ends his 25th birthday, safe and comfortable in his husband’s arms. 


End file.
